The black mold Aspergillus niger: flexibility as the key to success

In an article in Nature, CBS-KNAW researchers describe fungus Aspergillus niger's flexibility to turn on the production of different enzyme sets. This makes the fungus highly useful in producing enzymes for a large range of plant biomass substrates, allowing flexibility in the biotechnological process of biofuel production.

The ubiquitous fungus Aspergillus niger grows radially, forming long hyphae penetrating the substrate. It is an industrial fungus producing a various range of food additives but it is also responsible for food spoilage by causing the so-called black mold disease. Grown on sugar beet pulp, the by-product of sugar industry, we showed how different the response of different parts of one colony of this fungus are, depending on the availability of nutrients.

Swiss army knife

A. niger is able to turn on the production of different enzyme sets in different parts of its colony. Like a Swiss army knife, the fungus uses its enzymes to cut the polymeric structure of the sugar beet pulp and release simple sugars. In older parts of the colony, some components of sugar beet pulp have already been used and therefore different enzymes are needed for the substrate that has remained. In biotechnology these enzymes can be used to release sugars from plant biomass that can be used for bioethanol production.

The Centraalbureau voor Schimmelcultures (CBS) Fungal Biodiversity Centre - an institute of the Royal Netherlands Academy of Arts and Sciences (KNAW) and situated in Utrecht - maintains a world-renowned collection of living filamentous fungi, yeasts and bacteria. The Institute's research programs principally focus on the taxonomy and evolution of fungi as well as on functional aspects of fungal biology and ecology, increasingly making use of molecular and genomics approaches. The institute employs circa 90 personnel, among whom 20 scientists